1. Field of the Invention
The present invention relates to a refrigerant processing apparatus for collected equipment, which recovers a refrigerant from collected equipment using a refrigerant gas, such as a cooler for domestic use, an air conditioner, a refrigerator and an automobile cooler, without releasing the refrigerant into the air, and as required regenerates a recovered refrigerant and charges the regenerated refrigerant into the collected refrigerant, as well as to an oil separator which is connected to an existing refrigerant recovery system by piping and is used as a refrigerant processing apparatus for collected equipment.
2. Background Art
Refrigerant recovery and refrigerant charging have heretofore been carried out by different kinds of systems, respectively. Refrigerant charging systems have comparatively simple constructions which directly charge collected equipment with refrigerants recovered in their recovery bombs or refrigerants of new recovery bombs. On the other hand, improvements of refrigerant recovery systems have been targets of invention, and many kinds of refrigerant recovery systems have been invented and publicly known.
Many of these publicly known refrigerant recovery systems basically have a construction in which an oil-containing refrigerant of collected equipment is sucked by the suction of a compressor through an evaporating pipe having a suction regulating valve and is separated into a refrigerant and an oil, and a gaseous refrigerant is condensed into a liquid refrigerant by a cooling fan and a condenser to recover the liquid refrigerant into a recovery bomb through a condensation pipe, while the oil is recovered into an oil container. A refrigerant recovery system according to, for example, Japanese Patent Number 3,015,820 is publicly known as a representative invention based on the above-described construction (hereinafter referred to as the publicly known invention).
The refrigerant recovery system according to the publicly known invention will be described with reference to FIG. 15. A refrigerant and an oil are sucked from equipment from which to recovery the refrigerant, through an oil separator by a compressor, and the refrigerant is transferred under pressure to a condenser from an oil recovery container heated by a refrigerant of high temperature and high pressure which is ejected from the oil separator via the compressor. The oil from which the refrigerant has been separated by the heating of heating means is recovered in the oil recovery container, while the refrigerant from the outlet side of the condenser is stored into a container.
In a refrigerant recovery container in which the refrigerant is recovered, a bypass passage is provided between the outlet side of the compressor and the inlet side of the condenser, and a valve which opens and closes the bypass passage so that the refrigerant is returned to the condenser in part through the oil recovery container and in part through the bypass passage.
In particular, the publicly known invention saves power consumption by utilizing as the heating means for the oil recovery container the waste heat of the compressor instead of the heat of a refrigerant gas of high pressure and high temperature which is obtained on the outlet side of the compressor, and also provides mechanical connection between the compressor and the oil recovery container to transmit the vibration of the compressor to the oil recovery container, thereby releasing a gaseous refrigerant from the oil and liquefying the gaseous refrigerant to recover a liquid refrigerant.
However, the refrigerant recovery system constructed in the above-described manner according to the publicly known invention needs a complicated construction in which various devices for oil recovery are disposed in piping, and if collected equipment is to be charged with a refrigerant, a refrigerant charging system for transferring a refrigerant recovered in the refrigerant recovery container must be very uneconomically provided independently of the refrigerant recovery system.
In addition, since a refrigerant passage which passes from the condenser to the oil recovery container and back to the condenser goes to a high-pressure state within the oil recovery container, a liquid refrigerant necessarily remains in the oil recovery container at the time of the completion of recovery, with the result that insufficient recovery occurs, causing the problem that a refrigerant gas is released into the air when the kind of gas to be recovered is changed.
Furthermore, since the publicly known invention only aims to remove a liquid refrigerant from oil, a liquid refrigerant which contains a considerable amount of moisture is regenerated and recovered. If such a liquid refrigerant is directly charged into collected equipment, the cooling function and the mechanical durability of the collected equipment will be degraded. Accordingly, it is necessary to remove moisture from the liquid refrigerant as completely as possible before charging.
The invention provides an economical refrigerant processing apparatus for collected equipment, which efficiently recovers a refrigerant without releasing a refrigerant gas into the air and has a refrigerant regeneration and charging function. The invention also provides an oil separator which enables efficient recovery, regeneration and charging of a refrigerant of collected equipment by being connected to an existing refrigerant recovery system by piping.
To solve the above-described problems, the invention provides a refrigerant processing apparatus for collected equipment, for use in a refrigerant recovery system in which an oil-containing refrigerant to be recovered is sucked from collected equipment by a compressor and after an oil has been separated from the oil-containing refrigerant by an oil separator having a heater unit, a resultant refrigerant is regenerated as a liquid refrigerant by a condenser and is recovered into a recovery bomb. The refrigerant processing apparatus for collected equipment includes: the oil separator having a construction provided with a separating wall provided in a passage space defined in an upper portion inside a hermetically enclosed evaporating vaporization chamber, a heat exchanging double spiral pipe in which a double pipe made of a central pipe and an external pipe is formed spirally about a vertical central axis, the heat exchanging double spiral pipe being provided in a space below the separating wall, the oil-containing refrigerant being made to collide with the separating wall through the external pipe from below the heat exchanging double spiral pipe to separate the oil-containing refrigerant into a gaseous refrigerant obtained by volatilization or evaporation and an oil-containing liquid refrigerant, and a heating unit for vaporizing the oil-containing liquid refrigerant excluding the oil; an oil recovery channel in which a remaining oil is recovered by heating with the heating unit; a refrigerant regeneration and recovery channel in which a gaseous refrigerant obtained by separating the oil-containing refrigerant and heating the oil-containing liquid refrigerant excluding the oil, and a gaseous refrigerant remaining after regeneration and recovery or being produced by vaporization are passed into a condenser, then a condensed liquid refrigerant from the condenser is passed through the central pipe from above the heat exchanging double spiral pipe and is regenerated as a liquid refrigerant, and then the regenerated liquid refrigerant is recovered into the recovery bomb; and a refrigerant charging channel for charging the collected equipment with the liquid refrigerant regenerated from the gaseous refrigerant. In the refrigerant processing apparatus, recovery, regeneration and charging processes for the refrigerant to be recovered from the collected equipment are selectively controlled and carried out, and the external pipe through which the oil-containing refrigerant passes and the central pipe through which the refrigerant passes are mutually heat-exchanged to heat the oil-containing refrigerant and cool the refrigerant passing through the central pipe, thereby effecting efficient regeneration and recovery of the liquid refrigerant.
To solve the above-described problems, the invention provides an oil separator for a refrigerant processing apparatus for collected equipment, the oil separator including a heating unit for use in a refrigerant recovery system in which after an oil is separated from an oil-containing refrigerant of collected equipment, a liquid refrigerant is recovered into a recovery bomb through a condenser. The oil separator includes as its body an evaporating vaporization chamber made of a hollow body which is closed at its top and bottom by a top end plate and a bottom end plate, respectively, the evaporating vaporization chamber including in its interior a separating wall positioned below the top end plate and provided to define a passage space between the top end plate and a periphery of the separating wall, and a heat exchanging double spiral pipe including a central pipe which serves as a liquid refrigerant recovery passage, and an external pipe which serves as a recovery passage to communicate with the first recovery and charging passage during recovery, the heat exchanging double spiral pipe being formed spirally about a vertical central axis of the oil separator to prevent a refrigerant from staying in the heat exchanging double spiral pipe. The bottom end plate of the evaporating vaporization chamber is provided with a first pipe joint, a fourth pipe joint, a bottom heater and a bottom temperature regulating unit. The first pipe joint leads at one end to a branch passage constructed to switch between the first recovery and charging passage and a passage leading to the oil drain, and the other end of the first pipe joint is opened to the evaporating vaporization chamber as a port which serves as an oil outlet and a refrigerant inlet. The port and the external pipe of the heat exchanging double spiral pipe are formed as a recovery passage, and the first pipe joint is provided with a selector function valve which switches a flow passage to either one of the branch passage and the recovery passage. The fourth pipe joint is inserted through the bottom end plate and is connected to a bottom end of the central pipe of the heat exchanging double spiral pipe to constitute an outlet of a liquid refrigerant. The bottom heater for heating the evaporating vaporization chamber and the bottom temperature regulating unit are provided at a bottom surface of the bottom end plate. A second pipe joint and a third pipe joint are inserted through the top end plate or at the top of the evaporating vaporization chamber, and the second pipe joint is opened at one end inside the evaporating vaporization chamber and is connected at the other end to the second recovery and charging passage. The third joint is connected at one end to a top end of the central pipe of the heat exchanging double spiral pipe and is connected at the other end to the first condensed liquid pipe. The first recovery and charging passage is connected to the first pipe joint, and the fourth pipe joint is connected to the second condensed liquid pipe which leads to the recovery bomb.
According to the invention, the construction of the oil separator is such that the heat exchanging double spiral pipe in which the double pipe made of the central pipe and the external pipe is formed spirally about the vertical central axis of the oil separator is provided in a space below the separating wall, and the oil-containing refrigerant is passed through the external pipe from below the heat exchanging double spiral pipe, while the liquid refrigerant passed through the condenser is passed through the central pipe from above the heat exchanging double spiral pipe. Accordingly, while the oil-containing refrigerant is being passed through the external pipe, the oil-containing refrigerant is heat-exchanged to be heated by the heat exchanging double spiral pipe which is previously heated by the liquid refrigerant passed through the condenser. While the liquid refrigerant passed through the condenser is being passed through the central pipe, the liquid refrigerant passed through the condenser is heat-exchanged to be cooled by the heat exchanging double spiral pipe which is previously cooled by heat exchange with the oil-containing refrigerant. Since heat exchange is effected mutually between the central pipe and the external pipe in this manner, the entire heat exchange can be extremely economically effected to improve the yield of the liquid refrigerant.
According to the invention, the refrigerant processing apparatus includes: the oil separator; the oil recovery channel in which the remaining oil is recovered by heating with the heating unit; the refrigerant regeneration and recovery channel in which the gaseous refrigerant obtained by separating the oil-containing refrigerant and heating the oil-containing liquid refrigerant excluding the oil, and the gaseous refrigerant remaining after regeneration and recovery or being produced by vaporization are passed into the condenser, then the condensed liquid refrigerant from the condenser is passed through the central pipe from above the heat exchanging double spiral pipe and is regenerated as the liquid refrigerant, and then the regenerated liquid refrigerant is recovered into the recovery bomb; and the refrigerant charging channel for charging the collected equipment with the liquid refrigerant regenerated from the gaseous refrigerant. Accordingly, it is possible to extremely enhance the yield of a liquid refrigerant with respect to an oil-containing refrigerant to be recovered, which is transferred from the collected equipment.
Furthermore, in the case where the refrigerant regeneration and recovery channel is formed of two channels, the supply-side refrigerant regeneration and recovery channel and the circulation-side refrigerant regeneration and recovery channel, a gaseous refrigerant which cannot be fully regenerated by the supply-side refrigerant regeneration and recovery channel is circulated, reproduced and recovered by the circulation-side refrigerant regeneration and recovery channel. Accordingly, it is possible to recover a liquid refrigerant with extremely high yield, so that it is possible to prevent degradation of the cooling function and the mechanical durability of the collected equipment.
Part of the heat-exchanged oil-containing refrigerant is rapidly vaporized, while the remaining oil-containing refrigerant which is not yet vaporized drops to the bottom of the evaporating vaporization chamber. The remaining oil-containing refrigerant, because it is already heated, is rapidly vaporized excluding the oil by the heating unit and only the oil remains at the bottom. Because the interior of the oil separator becomes vacuum after the recovery of the liquid refrigerant, if an extremely small amount of gaseous refrigerant is transferred from above and the inner pressure of the oil separator is increased, the oil is ejected by a pressure difference when the oil drain valve at the bottom is undone. Accordingly, the oil can be easily taken out, and the gaseous refrigerant is hardly contained in an oil recovery container at the time of the completion of recovery and the amount of liquid refrigerant remaining in the oil can be extremely decreased.
In addition, according to the above-described construction, the gaseous refrigerant obtained by separation and heating in the oil separator and the remaining gaseous refrigerant as well as the gaseous refrigerant obtained by volatilization are all passed through the refrigerant charging channel, and therefore, do not at all lead to the release of a gaseous refrigerant into the air.
In addition, in the oil separator for the refrigerant processing apparatus according to the invention, the construction of the oil separator is such that the heat exchanging double spiral pipe in which the double pipe made of the central pipe and the external pipe is formed spirally about the vertical central axis of the oil separator is provided in a space below the separating wall, and the oil-containing refrigerant is passed through the external pipe from below the heat exchanging double spiral pipe, while the liquid refrigerant passed through the condenser is passed through the central pipe from above the heat exchanging double spiral pipe. Accordingly, while the oil-containing refrigerant is being passed through the external pipe, the oil-containing refrigerant is heat-exchanged to be heated by the heat exchanging double spiral pipe which is previously heated by the liquid refrigerant passed through the condenser. While the liquid refrigerant passed through the condenser is being passed through the central pipe, the liquid refrigerant passed through the condenser is heat-exchanged to be cooled by the heat exchanging double spiral pipe which is previously cooled by heat exchange with the oil-containing refrigerant. By effecting heat exchange mutually between the central pipe and the external pipe in this manner, it is possible to rapidly transfer a larger amount of the gaseous refrigerant to the compressor. In addition, in the case where the oil-containing refrigerant, after heat exchange, is vaporized by the heating unit such as the bottom heater at the bottom of the oil separator, since the oil-containing refrigerant is already heated by heat exchange, the liquid refrigerant can be economically vaporized in a short time, whereby it is possible to improve the efficiency of recovery, regeneration and charging of a refrigerant to be recovered.
In addition, the bottom end plate of the evaporating vaporization chamber is provided with the first pipe joint. The first pipe joint leads at one end to the branch passage constructed to switch between the first recovery and charging passage and the passage leading to the oil drain, and the other end of the first pipe joint is opened to the evaporating vaporization chamber as the port which serves as the oil outlet and the refrigerant inlet. The port and the external pipe of the heat exchanging double spiral pipe are formed as the recovery passage, and the first pipe joint is provided with the selector function valve which switches the flow passage to either one of the branch passage and the recovery passage. During the vaporized state of the liquid refrigerant, the remaining oil can be efficiently ejected, while when the regenerated liquid refrigerant is to be transferred to the collected equipment, the liquid refrigerant transferred from the circulation-side refrigerant regeneration and recovery channel can be efficiently ejected.
The fourth pipe joint is inserted through the bottom end plate and is connected to the bottom end of the central pipe of the heat exchanging double spiral pipe to constitute the outlet of the liquid refrigerant. The bottom heater for heating the evaporating vaporization chamber is provided at the bottom surface of the bottom end plate. The second pipe joint and the third pipe joint are inserted through the top end plate or at the top of the evaporating vaporization chamber, and the second pipe joint is opened at one end inside the evaporating vaporization chamber and is connected at the other end to the second recovery and charging passage. The third joint is connected at one end to the top end of the central pipe of the heat exchanging double spiral pipe and is connected at the other end to the first condensed liquid pipe. The first recovery and charging passage is connected to the first pipe joint, and the fourth pipe joint is connected to the second condensed liquid pipe which leads to the recovery bomb. The liquid refrigerant obtained by the condenser is passed through the central pipe from above the heat exchanging double spiral tube, whereby it is possible to construct a supply-side cooling and regeneration channel and to form part of a circulation-side cooling and regeneration channel. Accordingly, it is possible to provide an oil separator and a refrigerant processing apparatus both of which are extremely highly efficient.
In the invention, a float valve is used as the selector function valve which switches over the flow passage of the first pipe joint in the oil separator and the refrigerant processing apparatus, whereby the switching of the valve can be realized efficiently and economically.